Can Guarana increase testosterone levels?

[Justlooking5]

I came across this interesting study (granted it is in Wistar rats):

P. cupana = guarana seed. I've always had good body composition results with guarana in terms of leanness, and perhaps even increased muscle mass.

Animals treated only with P. cupana presented a significant increase in plasma testosterone levels and a significant increase in volumetric proportions of seminiferous tubules, which are indicative of spermatogenic stimulation.

Invalid Link Removed

 

[DennisTheDane]

Again in rats.... But maybe if you ramp up dosage and kill it!